1. Field of the Invention
The present invention is directed toward a railcar hatch cover assembly, and in particular, to a railcar hatch cover assembly in which the opening of a cover assists in the opening of another cover.
2. Description of Related Art
Covered railcars have long been used to transport materials such as grain to keep them covered during transport. Such railcars typically have a series of openings, or a single opening, in the top of the railcar through which the grain may be loaded. One or more hatch covers are associated with the opening(s) to close and seal the opening(s) during transport. The hatch covers typically lay flat horizontally when in the closed position and have a pivot on one side that allows them to rotate approximately 180 degrees to lay flat, upside down, horizontally in the open position. When opening the cover, energy must be applied to lift the cover from its horizontal closed position to a vertical position, but gravity applies the necessary energy to move the cover from the vertical position to the horizontal open position.
Hatch covers are typically provided in sets of three or more. The hatch covers are hinged along one or both edges. In one embodiment, the edges of adjacent hatch covers are in close proximity, and a series of battens overlies the edges of adjacent covers to provide a seal between the edges. With this type of cover assembly, it is necessary to release and pivot the battens away from the hatch covers in a separate operation prior to opening the hatch cover. In another embodiment, the ends of adjacent covers overlap to provide the seal. Due to the overlapping arrangement, it is necessary to open the covers in a particular order.
With either type of cover assembly described above, the covers must be physically lifted by an operator standing on top of the railcar to open and close the covers. The covers are relatively heavy to lift, and the operator must walk across the top of the railcar to open each of the covers. Due to the height of the railcar and the weight of the covers, opening and closing the covers poses an injury risk.
U.S. Pat. No. 5,572,932 to Early describes a railcar hatch cover system in which adjacent covers are linked with a cable so that as one cover opens, it assists in opening the adjacent cover to which it is linked. With this system an operator must still walk across the top of the railcar to open each cover individually, although the system relieves the operator from lifting the full weight of each cover.